Sorting apparatus

ABSTRACT

The invention relates to a channelizer or apparatus for sorting articles such as prepacked foodstuffs into channels each characterized by an individual weight band. The apparatus of the invention includes a weighting unit that weighs each article and produces information significant of the article weight that is transferred step by step through a train of preset registers storing channel weight band information until the transferred information agrees with the stored information. This agreement is effective to cause transfer of the article to the channel to which the stored information relates.

United States Patent 72] Inventor Scott Cunningham Whiteford Highs/cape,Bayleys Hill, Nr. Sevenaahs, Kent, Croydon, England [21] Appl. No.883,423 [22] Filed Dec. 9, 1969 [45] Patented Dec. 14, 1971 54] SORTINGAPPARATUS 8 Claims, 4 Drawing Figs.

[52] 1.1.8.01 209/121 [51] 1nt.C1 1307c 5/16 [50] Field of Search209/74, 121; 177/25, D16. 18; 235/58, 61

[56] References Cited UNITED STATES PATENTS 3,291,232 12/1966 Bell235/58 X 3,446,299 5/1969 Leonowicz 3,460,673 8/1969 Sanner PrimaryExaminerAllen N. Knowles Assistant Examiner-Gene A. Church Anamey-lfiurtKelrnan ABSTRACT: The invention relates to a channelizer or apparatusfor sorting articles such as prepacked foodstuffs into channels eachcharacterized by an individual weight band. The apparatus of theinvention includes a weighting unit that weighs each article andproduces information significant of the article weight that istransferred step by step through a train of preset registers storingchanrnel weight band information until the transferred informationagrees with the stored information. This agreement is effective to causetransfer of the article to the channel to which the stored informationrelates.

72) Transfer 01 m if 7b Integrator To ontno/ Unit 5 Patented Dec. 14,1971 4 Sheets-Sheet 2 w n QM, mm mm mm 4 I I n w E & w v m m N Qi||||||||l TIIIILIIFIT I @A I 1 I Til mm c fll QQ m A ww S t l fi MH mFIIZIL mm mm Tr Patented Dec. 14, 1971 4 Sheets-Sheet 5 SORTINGAPPARATUS This invention concerns sorting apparatus of the kind adaptedto respond to a selected physical characteristic of each of a series ofarticles and to distribute such articles amongst channels eachsignificant of a particular value or value range of the characteristicin question. Such apparatus may conveniently be termed a channelizer"and will be so called herein.

The invention is more particularly concerned with a channelizer that isadapted to sort articles in accordance with their individual weights,for instance for the pricing of prepacked foodstuffs in accordance withthe weight of a pack. The object of the invention is to provide achannelizer for such purpose that may reliably a fast rate into arelatively large number of channels each significant of an articleweight range that may be limited by weight values selected arbitrarilyto coincide with monetary or other values that bear a selectedrelationship to the weight of a sorted article.

A channelizer in accordance with the invention comprises a conveyor forarticles to be sorted, a plurality of channels and transfer meansassociated with each channel for transferring an article from saidconveyor to an individual channel; a weighing unit for sensing theweight of each article carried by the conveyor and adapted for producinga signal significant of the weight thereof; a register associated witheach transfer means and adapted to store a signal significant of theweight range characteristic of the related channel; sequence meanssynchronized with movement of articles by said conveyor for activatingeach register as an individual article coincides with the transfer meansassociated with said register; and a coincidence detector for comparingthe signal from the weighing unit with the associated stored registersignal and for actuating the related transfer means when theweight-significant signal of an article coincident with said transfermeans matches the related stored register signal.

Preferably the registers comprise digital stores, e.g., binary digitalstores, and the signal produced by the weighing unit is digitized forcomparison with a stored digital register signal by the relatedcoincidence detector. Thus conveniently, an analogue weight signal,e.g., a voltage signal, is produced by the weighing unit and digitizedby a digital counter that receives input pulses under the control of acomparator that compares the weight signal with the output of adigital/analogue converter reading the counter state.

The apparatus desirably includes a scaling unit that transforms weightsignals in a preselected manner whereby the transformed signal may bedigitized in terms of arbitrarily selected units, for example, priceunits. Thereby, each channel may be arranged to receive articles havinga weight range that is delimited by the selected units which, if priceunits, means that each channel will receive articles of a value rangedelimited by convenient units of monetary value.

A channelizer in accordance with the invention may be associated withlabelling equipment adapted to label each sorted article so as to showthereon its weight and/or price and/or other information related to thechannel into which the article is transferred.

A typical embodiment of the invention will be described in relation tothe accompanying drawings, in which:

FIG. l is a schematic block diagram illustrating certain units of achannelizer according to the invention;

FIG. 2 is a block diagram illustrating further units of the channelizer;and

FIG. 3 is a timing diagram illustrating the operational sequence of theunits of the channelizer.

FIG. 4 is a partially schematic, partially diagrammatic isometric viewof an illustrative channelizer according to the invention.

In a typical embodiment of the invention such as that illus' trated inthe drawings, articles to be sorted such as prepacked foodstuffs, arecarried by a conveyor successively past a weighing unit. As an articlepasses said unit, a voltage signal significant of its weight isgenerated and, during a short sample period, that signal integrated andstored. The stored signal is then transformed by a scaling unit and sentto a voltage comparator while a clock generator is started. The clockgenerator supplies a train of pulses to a binary counter and adigital/analogue converter reads the counter and presents to thecomparator a voltage that is proportional to the state of the counter.When the input voltage :from the scaling unit and the voltage from theconverter reach equality, signifying a counter state that is a digitizedrepresentation of the input voltage, the comparator stops the clockgenerator.

The conveyor and the mechanical components of the equipment are notillustrated in detail since these may take a variety of forms, as willbe apparent to those familiar with article-sorting mechanisms and indeedwill be designed so as to be suitable for handling articles of theparticular type to be sorted by an equipment in accordance with theinvention. The conveyor may for instance comprise a guideway along whichthe articles are propelled by pegs or slats on a suitably intermittentlydriven endless chain. Preferably the conveyor is formed in two parts,the first part (feed conveyor) being adapted to feed articles one at atime to a platform associated with the weighing unit, and a second part(output conveyor) that is adapted to convey the articles from suchplatform past a series of lateral channels each having a suitableactuator constituting the said transfer means and adapted to displace anarticle on the output conveyor into its associated channel in responseto a signal as hereinafter described. The actuators may be electricallyoperated (e.g., solenoid thrustors) or pneumatic or hydraulic ramassemblies with electric control of their operation.

The weighing unit is preferably of the strain gauge type, the platformbeing supported on a suitable beam system the deflection of which underload is measured electrically by strain gauges, since this arrangementcan be designed to produce accurate weightsignificant outputs with verysmall platform displacements and, consequently, rapid response sopermitting a high rate of article sorting to be accomplished.

Referring to FIG. ll of the drawings, this shows an integrator 1 thatreceives over line 2 from the weighing unit the output voltage generatedby the latter and integrates this voltage during a sampling period. Theoperation of the integrator l is controlled by an input clamp circuit 3in turn controlled by an integrator control unit 4 that responds to thepresence of an article on the platform of the weighing unit. In thepresent embodiment, a photocell is arranged to produce a signal on line5 when an article is fed, by the feed conveyor, onto the platform of theweighing unit, the signal on line 5 being arranged, after a suitabledelay, to deactivate the clamp circuit 3 and so permit the integrator lto respond to the voltage on line 2 for the sampling period that isdetermined by the unit 4.

The delay between arrival of a signal on line 5 and the commencement ofthe sampling period is so selected, in accordance with the responsecharacteristic of the weighing unit, that the first overshoot" of theweighing unit signal voltage beyond the level corresponding to the exactweight of the article and due to inertia, does not fall within thesampling period. Accordingly, the integrator l is only activated for asampling period (for instance 50 ms.) in which the deviation of thevoltage on line ll from a mean value corresponding to the true weight ofthe article is small and rapidly decreasing. The integrator l is thusenabled to produce an output (on line 6) that reflects the true weightof the article to a high degree of accuracy.

FIG. 1 also shows (diagrammatically) a potentiometer 7 that constitutesthe said scaling unit which reduces the output voltage on line 6 to avalue that is a selected proportion of the line 6 voltage. The scalingunit 7 is set in accordance with, for instance, the price per unitweight of the articles being sorted so that the reduced voltage issignificant of the value of an article having a weight represented bythe output voltage on line 6. This reduced voltage is applied over line8 to the input of a comparator 9.

Also as shown in FIG. l, the signal on line 5 that initiates operationof the integrator it (after said delay) is also conducted over line to aclock generator control unit 11. The latter, in response to such signalon line 10, establishes an output voltage on a line 12 which transmitsthis voltage both to the integrator l and to an "AND" gate 13. Thevoltage transmitted to the integrator "zeros" the output of the latterprior to commencement of the sampling period while the voltagetransmitted to the gate 13 prepares this to pass clock pulses from aclock generator 14 to a binary counter 15. The line 3 from the unit 4also extends, via a further AND gate 16, to the gate 13 whereby, at thecommencement of the sampling period the gate 13 is opened and clockpulses are applied to the counter 15.

The counter 15 has duplicated outputs one set of which is connected to adigital/analogue converter 17 that generates a voltage on its outputline 18 corresponding to the instantaneous state of the counter 15. Thisvoltage on line 17 is applied to the comparator 9 which compares thisvoltage with that on line 8 and so long as there is a difference betweenthe voltages on lines 8 and 17 applies a gate-opening voltage over line19 to an input of gate 16.

Thus the voltage on line 3 during the sampling period holds gate 16 openso long as there is a voltage difference between line 8 and 17 andtherefore clock pulses are accumulated by the counter 15 until thisdisplays, by voltages on its outputs, a stored count significant of thevoltage on line 8; that is, in the case considered, a count significantof the value of the article then on the platform of the weighing unit.

In the embodiment to which the drawings relate, a counter staterepresenting more than 21 received clock pulses signifies an overweightarticle that is to be specially handled. For this reason, the gate 16has a third input (line 20) from an AND" gate 21 connected to theappropriate counter outputs so that if the counter state exceeds thevalue of 2! received clock pulses the gate 16 is closed regardless ofthe voltage then appearing on line 19 from the comparator 9.

When gate 16 closes and voltage thereby removed from its output, thisfact is also transmitted by a line 22 connected both to a first shiftpulse generator 23 and to a resetting connection on the unit 11; thelatter is reset to remove the voltage on line 12 while the generator 23produces a pulse adapted to read out the state of counter 15 and totransfer this to a first buffer register 24. This readout also resetsthe counter 15 to zero.

As above described, the conveyor is intermittently driven and in thecase of a two-part conveyor as described, the output conveyor partthereof is intermittently advanced through steps equivalent to theseparation of the channels along the path of this conveyor. in general,the first channel will be more than one step from the weighing unitplatform and the equipment will include buffer registers equal in numberto the output conveyor steps between the weighing unit platform and thefirst channel. As explained above, the first bufier register 24 receivesthe state of counter 15 while an article is on the platform of theweighing apparatus: the information represented by this counter state istransferred to the second and successive buffer registers in synchronismwith the movement of the output conveyor and it will be apparent thatthis information will reach the final buffer register when the articleto which the information relates is one step from the first channel.

In the embodiment shown in the drawings, there are in fact two bufferregisters, the second being shown at 24a in HQ. 2.

The equipment further comprises a binary register associated with eachchannel. Each such register is associated with a coincidence detectorand is preset to a state significant of, e.g., the value of the articlesto be transferred to the related channel.

A sensing device (not shown), in this instance a magnetic proximityswitch. detects the presence of an article on the output conveyor in thefirst position reached by that article after leaving the weighing unitplatform. This sensing device produces a voltage pulse on line 25 (FIG.2) that activates a second shift pulse generator 26. The latter producesa pulse on line 27 that is applied to each buffer register and to eachsaid binary register to transfer the information in the first bufferregister to the second and so on, the information in the final bufferregister to the binary register associated with the first channel, andso on to the binary registers associated with the second and subsequentchannels. The pulse on line 27 also goes to a zeroing pulse generator 28which produces a pulse effective to zero the register 24 as soon as itsstate has been transferred to the second buffer register 24a.

Thus as an article travels on the output conveyor, information as to thevalue of that article is transferred step by step through the successivebuffer registers and then through the binary registers associated withthe successive output channels, the information reaching the binaryregister associated with any given channel as the article reaches aposition to be transferred to that channel.

When an article reaches a channel into which it is required to betransferred, the value-significant information relating to the articlewill correspond with the presetting of the binary register of thatparticular channel and to which register such information will have beentransferred as the article came into position for transfer to thatchannel. information relating to the article As shown in FIG. 2, thevoltage pulses on line 25 also go via delay and timing circuits 29, 30to an interrogation circuit 31 of each binary register (the block 32 inFIG. 2 represents all the binary registers and their coincidencedetectors); in the case of any such register which at this time ispreset to a state corresponding to the value-significant informationthat has just been transferred to that register, the associatedcoincidence detector responds and actuates the transfer mechanism (viadrives indicated at 33 in FIG. 2) of the corresponding channel. Therebyall articles on the output conveyor that are in a position to betransferred to a desired channel are so transferred.

It will be noted in FIG. 2 that the line 27 extends to an OR" gate 34which is also connected to a pulse generator 36, whereby a pulse on line27 or from the generator 36 will be transmitted to a line 35 thatextends to the digital/analogue converter 17. The generator 36 is alsoconnected by a line 37 to the registers comprising the block 32. A pulseon line 35 is effective to zero the converter 17 while a pulse on line37 is effective to zero the registers of block 32.

Thus, during normal operation the pulse on line 27 that accomplishestransfer of information from one register to another as hereinaboveexplained is also effective to zero the converter 17 to prepare this forits next conversion operation.

The pulse generator 36 is arranged to produce a pulse whenever theequipment is switched on after a shutdown and it will be seen that thispulse zeros the converter 17 in the event that it had not been zeroedprior to shutdown and, also, the registers of block 32 are zeroed topreclude the subsequent transfer of information being disturbed byspurious information retained or introduced by switching transients onshutdown.

FIG. 3 illustrates diagrammatically the timing of the various functionsof the equipment. The respective horizontal lines represent voltages orfunctional states, as the case may be, of various components against acommon horizontal time scale. The lines in the drawing are marked withthe references used in H08. 1 and 2: for example the top line is marked25 and shows the voltage state of line 25 in FIG. 2.

The importance of the scaling unit 7 in the described embodiment shouldbe noted. Since there is conversion of an analogue voltage to a binarycode, by use of the scaling unit each unit of that code can be made torepresent either a discrete increment of weight or of price. if, as maybe the case, the coded signal is used for the control of a weight/pricecomputing printer, considerable advantage is to be gained both inreliability and simplicity. For example, by appropriate scaling, aparticular code may represent 7% oz. and 2s. Il /ad. and the code maythus be used directly to program print wheels in a fairly simple manner,avoiding conversion of weight analogue information to the lowestincrement (say 7% oz. to 62 pulses each representing A; oz), conversionof price/lb. information to the lowest increment (say 54d./lb. to 108pulses each representing /2d.), multiplying the two together, dividingby 128 a 02. in llllb), dividing by 2 to convert to pence, dividing by12 to convert to shillings and so on.

FIG. 4 depicts, in a very general way, an illustrative channelizeraccording to this invention. As shown, channelizer 40 comprises a hopper41 which intermittently feeds workpieces 42, for example, prepacked foodsuch as cheese and cooked meats, onto a continuously rotating conveyorbelt 43, called the feed conveyor. As the belt 43 rotates, it advancessuccessive workpieces 42 onto the platform 44 of a weighing transducer46, the output thereof being connected to integrator circuit l inFIG. 1. As a workpiece arrives on platform 44 it interrupts the lightbeam from a lamp 47 and a lens 43 to a photocell 49, thereby signallingits arrival to control unit 5 in FIG. 1. After the workpiece on platform44 has been weighed, it is passed to a second conveyor belt 51 where itis advanced past a plurality of actuators 52 rotatably mounted on theshafts 53 of a corresponding plurality of solenoid thrusts 54. Thearmatures of motors 54 are connected to the transfer drives 33 (FIG 1)and when a given motor is energized to rotate the correspondingactuator, the workpiece positioned proximate that actuator is deflectedoff conveyor 51 to fall into a storage bin 56, as discussed withreference to FlGS. 1-3.

lclaim:

ll. A channelizer comprising:

a conveyor for articles to be sorted;

a plurality of channels;

transfer means associated with each said channel for transferring anarticle from said conveyor to an individual channel;

d. a weighing unit for sensing the weight of each article carried by thesaid conveyor and adapted for producing a signal significant of theweight thereof;

. a register associated with each said transfer means and adapted tostore a signal significant of the weight range characteristic of therelated channel;

. sequence means synchronized with movement of articles by said conveyorfor activating each said register as an individual article coincideswith the said transfer means associated with said register; and

g. a coincidence detector for comparing the signal from the saidweighing unit with the associated stored register signal and foractuating the related transfer means when the weight-significant signalof an article coincident with said transfer means matches the: relatedstored register signal.

2. The channelizer of claim l in which each said register comprises adigital store and the signal produced by the said weighing unit isdigitized for comparison with a stored digital register signal by therelated said coincidence detector.

3. The channelizer of claim 2 in which an analogue weight signal isproduced by the said weighing unit and digitized by a digital counterthat receives input pulses under the control of a comparator thatcompares the weight signal with the output of a digital/analogueconverter reading the counter state.

4. The channelizer of claim 3 in which said weighing unit produces anelectrical signal significant of article weight, the apparatus includingmeans for integrating a sample of said signal during a period ofcommencing subsequent to the first overshoot of the said signal.

5. The channelizer of claim 1, including a scaling unit for transformingweight signals into signals significant of value, said registers storingsignals significant of the values of articles to be sorted into therespective channels.

6. The channelizer of claim 5 in which said weighing unit produces avoltage signal significant of article weight and said scaling unitcomprising a voltage divider.

7. The channelizer of claim 6 including means for integrating a sampleof said voltage signal during a period commencing subsequent to thefirst overshoot of the said signal and in which said scaling unit isadapted to receive and divide a voltage S Ifilml roduced by saidintegratin means.

8. e c annelizer of claim 11 rnclu mg labelling equipment

1. A channelizer comprising: a. a conveyor for articles to be sorted; b.a plurality of channels; c. transfer means associated with each saidchannel for traNsferring an article from said conveyor to an individualchannel; d. a weighing unit for sensing the weight of each articlecarried by the said conveyor and adapted for producing a signalsignificant of the weight thereof; e. a register associated with eachsaid transfer means and adapted to store a signal significant of theweight range characteristic of the related channel; f. sequence meanssynchronized with movement of articles by said conveyor for activatingeach said register as an individual article coincides with the saidtransfer means associated with said register; and g. a coincidencedetector for comparing the signal from the said weighing unit with theassociated stored register signal and for actuating the related transfermeans when the weightsignificant signal of an article coincident withsaid transfer means matches the related stored register signal.
 2. Thechannelizer of claim 1 in which each said register comprises a digitalstore and the signal produced by the said weighing unit is digitized forcomparison with a stored digital register signal by the related saidcoincidence detector.
 3. The channelizer of claim 2 in which an analogueweight signal is produced by the said weighing unit and digitized by adigital counter that receives input pulses under the control of acomparator that compares the weight signal with the output of adigital/analogue converter reading the counter state.
 4. The channelizerof claim 3 in which said weighing unit produces an electrical signalsignificant of article weight, the apparatus including means forintegrating a sample of said signal during a period of commencingsubsequent to the first overshoot of the said signal.
 5. The channelizerof claim 1, including a scaling unit for transforming weight signalsinto signals significant of value, said registers storing signalssignificant of the values of articles to be sorted into the respectivechannels.
 6. The channelizer of claim 5 in which said weighing unitproduces a voltage signal significant of article weight and said scalingunit comprising a voltage divider.
 7. The channelizer of claim 6including means for integrating a sample of said voltage signal during aperiod commencing subsequent to the first overshoot of the said signaland in which said scaling unit is adapted to receive and divide avoltage signal produced by said integrating means.
 8. The channelizer ofclaim 1 including labelling equipment responsive to weight-significantsignals derived from said weighing unit and adapted to label eacharticle with information related to the channel to which it is to betransferred.